KING: Video of those protests show crowds chanting for shop owners to close their businesses. Economic protests erupted in several cities around Iran earlier this year. And NPR's Peter Kenyon is following the story from Istanbul. Hey, Peter.

PETER KENYON, BYLINE: Hi, Noel.

KING: So what's going on in these most recent protests in Iran?

KENYON: Well, there were big crowds at the Grand Bazaar. You heard a bit of it. They weren't shopping, though, just demonstrating. And there were protests also outside the Parliament. Iranians have basically been under pain of a falling currency for some time now. The buying power is weak. The retail sector's suffering at - has ripple effects - some extremely sharp recent drops. The Iranian media say the rial fell to 90,000 to the dollar on the black market. Now, the official rate's 42,000.

KING: Wow.

KENYON: So this protest is getting a bit more attention because it happened in Tehran. But there have been protests on and off for months now in other cities.

KING: So what is the Iranian government saying?

KENYON: Well, the government says the United States is to blame for all of this. Iran's economy was already underperforming before Donald Trump pulled out of the 2015 nuclear deal. But it's gotten worse since then, especially with American sanctions coming soon. President Hassan Rouhani tells state TV it's part of a longstanding desire in Washington to topple the Iranian government - something they've failed to do for decades. We're also seeing reports now that some of these demonstrators have been arrested and may not be released on bail. So the government's taking it seriously.

KING: Well, given that Iran does not have control over what the U.S. does regarding sanctions, is there anything that Iran can do to shore up its economy?

KENYON: Well, good question; Iran's central bank says it's creating something called a secondary currency market. They say that might ease the tensions, relieve the pressure on the currency. I'm not clear exactly on how that's going to work. We'll have to see. More broadly, Iran is working with Europe and Asia to devise ways of keeping trade going in the face of U.S. sanctions. A big key will be the energy sector. Iran needs to get paid for its oil and gas sales. That's a huge chunk of their revenue. And that may not be possible through normal banking channels once the sanctions kick in. India, one of Iran's big buyers, just reached that conclusion. It says it may revert to some other kind of back channel it's used in the past.

But there's also a domestic political aspect to this. With regard to the nuclear agreement, Rouhani is under pressure from hard-liners, and so the government is very publicly positioning itself to pull out of the deal itself if necessary and ramp up its nuclear activity. That would only make things worse for the economy. So there's a lot in play right now.

KING: Well, no country wants its citizens demonstrating in the streets. How much trouble, I wonder, is the Iranian government in over this?

KENYON: Well, there's no question they're taking it very seriously. I mean, at home, as we said, President Rouhani, he's a pragmatist. He gets support from the moderates and reformers. But he is under heavy pressure from hard-liners and has been ever since he won re-election last year. Now, at the same time, the Trump administration's stated goal is to increase economic pressure on Iran until Tehran is forced to come back to the negotiating table. Trump wants a tougher nuclear deal, an agreement on missiles and other things. So the government's economic struggles are encouraging hard-liners in Iran that they might be able to take back the president's - from Rouhani; if not right away, then in the next election, which is still about three years off. Rouhani had very strong support at the ballot box last year, but continuing economic woes are the biggest threat to that public support.